Pneumatic piano.



C. A. LAMBERT.

PNBUMATIG PIANO.

APPLXGATION FILED 111111124, 1912.

Patented Aug. 11, 1914.

UNITED sTATEs PATENT oEEIoE.

CLAYTON A. LAMBERT, OF INDIAN VIEW, OHIO, ASSIGNOR TO THE JOHN CHURCH COMPANY, OF CINCINNATI, OHIO, A CORPORATION 0F OHIO.

PNEUMATIC PIANO,

Specification of Letters Patent.

Patented Aug. 11, 1914.

Application filed .Tune 24, 1912. Serial No. 705,407.

To all whom it may concern Be it known that I, CLAYTON A. LAMBERT, a citizen of the United States, and a resident of Indian View, Hamilton county, State of Ohio, have invented certain new and useful Improvements in Pneumatic Pianos; and I do declare the following to be a clear, full, and exact description of the invention, attention being called to the drawing which accompanies this application and. forms a part thereof.

This invention relates to certain new and useful improvements in pneumatic piano players.

It consists more particularly of features of construction used in connection with the means and devices concerned in the control and passage of the air, all as described more fully hereinafter' and pointed out in the claim.

The features of the invention are illustrated in the accompanying drawing, in which Figure 1 shows in vertical cross-section most of the upper part of a pneumatic piano player of a customary type. Fig. 2, shows a part of this view on an enlarged scale, it being more particularly a vertical section of one of the pneumatic elements. Fig. 3, shows part of a top-view of such an element.

Numeral 5, indicates one of the hammers of the piano action and is adapted to co-act with a complementary string 6, when actuated bv means of a lifter-rod 7, sometimes also called an abstract, and by a series of intervenient instrumentalities of which the most essential ones are shown. A detailed description of these parts is omitted. since no novelty is claimed for them. Rods 7 may be actuated by key-levers 8, in case provision is made for manual playing of the instrument. In case of pneumatic operation, levers 9 serve. which act upon the lifterrods by means of noses 10 thereon, there being a lever for each lifter-rod 7. Levers 9 vare held in normal, that is inoperative posit-ion, by the weight of lifter-rods 7 and the connected parts, which action may be augmented by springs 11. Levers 9 are actuated by pneumatic elements A which act upon them by means of push-rods 12, it being of course understood that there is such an element, a connected push-rod 12, lever 9 and lifter-rod 7 for each hammer. The operation of the pneumatic elements for the purpose of acting on their respective hammers is controlled by the usual perforated music-sheet 13, co-acting with a tracker-bar 14, while passing between rotary spools 15 and 16, one of which is driven. This controlling action is transmitted to the pneumatic elements by means of tubular conduits 17, one leading to each element and in open communication with wind-chests B. A vacuum is maintained in these latter which by means of ducts 32 extends to conduits 17 and is derived from the action of the usual vacuum-motor or pumpers, in connection with. a General suction-chamber with which these chests are in open communication by means of a conduit 18.

The pneumatic elements are substantially bellows consisting each of a base-plate 19, whereby they are attached to the windchests, of a movable flap 20 and of a flexible Side 21, connected to both, the whole forming a collapsible inclosure which may be distended to the extent permissible by the stretch of fiexible side 21. Normally, these elements are held in their expanded condition, holding up flaps 20, by levers 9, while these latter are also in their normal position, and by rods 12 which connect said levers and said flaps as before described. This connection as to the rods is by two spaced screw-washers 22-22, which engage between them fingers 23, one extending from each flap. Normally, elements A are open to the atmospheric air by means of conduits, consisting each of an outer or air-port 24, an inner port 25 and a duct 26, which connects both ports. These latter are located in the base-plate of the elements, while the ducts are formed below the underside of the base-plates and in the outer side of the uppe-r wall of the wind-chest.

27 is a suction port by which communication may be established between duct 26 and the interior of the wind-chest, which communication is subject however to control by a valve 28, contained in a valve-chamber formed by an enlargement of duct 26. This port 27 is alined with port 24 and valve 28 is adapted to close either one, it being free to move in the space between these two ports, a seat for it being provided around each port, one seat being formed on the underside of base-plate 19, and the other on the bottom of duct 26. A stem 29 is provided for proper guidance oi the valve, engaged by two guides 30-31, to direct the movement of the saine.

Tubes 1'? con'nnunicate with chest B as be- 5 tore described, and by means of ducts 32, 'formed in the lower wall of the wind-chest and which. ducts are enlarged to form airchambers 33 one below each port 27. A flexible diaphragm 34rcloses each air-chamand upon this diaphragm there rests a pushbutton 35, atlixed to the lower end of the valvestem.

Normally the parts are in the position shown in F 2, that is to say, valve 28 closes port 27 to maintain the vacuum in chest l, which vacuum extends through duct 82 and tubes tracker-bar, which openings are also closed by the intact portion ot the music-sheet. llt now one ot' the pertorations in this latter passes over an opening` in the tracker-bar, air is instantly admitted to the particular tube reducing,` momentarily the vacuum. The admitted air rushes to the chest and while passing through duct 32 and through air-chamber 33, iills this latter instantly, thereby creating; an impulse which by its reaction upon diaphragm t4 causes this latter to bulge upwardly. This movement ot the diaphragm through the intervention ot the push-button restingY upon it, throws valve '2S off trom its seat and opens port 27. rEhe same movement also raises the valve against port 2li, so as to close this latter, thereby cutting ott the outer air from the interior ot element A.. rlhis latter is now in open communication with the wind-chest and inasmuch as the limited quantity of air entering),` through the tracker-bar and admitted to the chest is insuilicient to overcome the preponderating1 counter-action of the vacuum therein, the air is instantly sucked out ot element A.. A collapse ot this latter tollows, causing` actuation of the corresponding' lever 9, by means ot rod 12 and a soundproducing,1 operation of the corresponding hammer 5. Closure ot the opening` in the trac rer-bar by the controller sheet, whereby the outer air is cut otl2 trom the wind-chest, restores the parts to their normal and inactive positions.

'lfo permit adjustment and regulation of the operation of each individual pneumatic element with referenceto its corresponding` hammer, regulating means are provided as for instance screws 8G, one seated in each lever 9 and adapted to co-act with a stopbar 37.

lt is essential, in order to insure prompt action ot the pneumatic elements, to have the air-way to them from the outside as well :trom chest l5, as short and direct as possible. This is obtained by the means shown, that is by havingducts 26 immediately beber toward the interior or" the wind-chest it' to the openings in the` and by locating the airso as to be low each clement fr, port 24C and the suction port 27,

' in direct communication with this duct.

The operation of the valves is quite sensitive and quickly affected by disarrangement or slight obstructions. rllie pneumatic elements are subject to detects like leakage for instance and effects of wear. rhis requires close attention and makes frequent access to these elements and valves necessary. lt is desirable and quite essential that such access may be had quickly and direct without disturbing other parts not involved. l accomplish this by making; removal of each individual element possible, tor which purpose each is separately attached by screws 38 which engage the extended base-plate 1S) of each element and are seated in the upper wall ot the wind-chests. By removingI these screws, any element may be taken out, independently and without interfering with any other and inasniucl'i as the extended part of these base-plates forms also the top of the valve-chambers below them immediate access to these valve-chambers is had at the same time. Repairs and renewal ot parts, duplicate parts being7 on hand, may thus be quickly made, without interfering with the use ot the piano to any appreciable extent. This is of great advantage in View of the tact that many of these instruments are used under circumstances where interference with their use 'is very objectionable, as for instance where they are rented out, or used in public places.

Having' described my invention, l claim as new:

A pneumatic action for pneumatic pianos, comprisingl a collapsible element which consists of a movable 'flap and of a base-plate to which the Hap is secured by a collapsible side, the base-plate being` extended at one of its ends beyond the flap and provided with two pertorations which extend through its entire thickness, one ot them being located below the tlap and constituting a suction port for the element, the other one being,` located in the extended part ot the base-plate to form an air-port, a wind-chest which coniprises two spaced walls one of which is pert'orated to form a suction-port, the perforation being' equal in diameter to the air-port mentioned, this suction-port beingcircumterentially enlarged kbetween inner and outer sides of the wall in which it is located to form within the thickness of said wall a alve seat, also a valve-chamber above said seat which chamber is contiguous to the outer side of the wall, there beine` also a duct within the thickness ot this wall which extends laterally from said valve-chamber and is open on the outer Side of said wall, the element being secured at its base-plate against said outer side and in a manner that the air-port in the extended part ot said base-plate registers with the suction-port in the wind-chest and that the suction-port in said base-plate alines with the end of the duet below the base-plate so that this latter serves also to cover said duct, and a valve contained in the valve-chamber mentioned and movable in the space between the valveseat therein `and the under side of the extended part of the baseplate and adapted l0 to close either the air-port in said base-plate,

or the suction-port in the Wind-chest, thereby controlling communication of either of these ports with the duct which leads to the element.

In testimony whereof, I hereunto aix my 15 Copie! of this patent my be obtained for ive vente each, by addressing the Commissioner of ratente. Washington, D. c. 

